Outcomes of venetoclax-based therapy in patients with t(11;14) light chain amyloidosis after failure of daratumumab-based therapy.

Background: Daratumumab's incorporation in the upfront treatment of light chain (AL) amyloidosis has led to daratumumab (dara) refractoriness early in disease course. Patients who experience relapse or have suboptimal response to dara-based-therapy, have limited options.

Objective: This study aimed to evaluate the outcomes of venetoclax-based therapy in t(11;14) positive AL patients who previously failed dara.

Methods: Thirty-one patients with AL were included in this bi-institutional retrospective analysis.

Results: Dara failure was due to inadequate response in 20 (65%) patients, haematologic relapse in 7 (22%), and both haematologic plus organ relapse in 4 (13%). Overall haematologic response rate to venetoclax-based therapy was 97%, with ≥ VGPR being 91%. Of the 19 evaluable patients with cardiac involvement, 14 (74%) achieved organ response. Of the 13 evaluable patients with renal involvement, 6 (46%) achieved organ response. With a median follow-up of 22 months, median time-to-next-treatment (TTNT) and overall survival (OS) were not reached. The 12- and 24-month TTNT rates were 74% and 56%, respectively. At data-cut-off, four patients had died, all from AL-related organ complications. The 12- and 24-month OS rates were 89% and 85%, respectively. Grade ≥3 adverse events occurred in 26% of patients, with 6% due to infections.

Conclusion: These findings are encouraging for the use of venetoclax as salvage therapy post-dara failure.